Amorphous and graphitized nitrogen-doped (N-doped) carbon spheres are investigated as structurally well-defined model systems to gain a deeper understanding of the relationship between synthesis, structure, and their activity in the oxygen reduction reaction (ORR). N-doped carbon spheres were synthesized by hydrothermal treatment of a glucose solution yielding carbon spheres with sizes of 330 ± 50 nm, followed by nitrogen doping via heat treatment in ammonia atmosphere. The influence of a) varying the nitrogen doping temperature (550-1000 °C) and b) of a catalytic graphitization prior to nitrogen doping on the carbon sphere morphology, structure, elemental composition, N bonding configuration as well as porosity is investigated in detail. For the N-doped carbon spheres, the maximum nitrogen content was found at a doping temperature of 700 °C, with a decrease of the N content for higher temperatures. The overall nitrogen content of the graphitized N-doped carbon spheres is lower than that of the amorphous carbon spheres, however, also the microporosity decreases strongly with graphitization. Comparison with the electrocatalytic behavior in the ORR shows that in addition to the N-doping, the microporosity of the materials is critical for an efficient ORR.
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http://dx.doi.org/10.3762/bjnano.11.1 | DOI Listing |
Mikrochim Acta
December 2024
Chemistry Institute, Federal University of Uberlândia, Uberlândia, MG, 38408-100, Brazil.
Babassu (Atallea sp.), a native palm tree from South America's Amazon produces bio-oil and biochar with significant potential for industrial applications. Babassu oil as a bio-based plasticizer is reported here for the first time to replace petrochemical alternatives in the production of conductive filaments for additive manufacturing purposes.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, PR China. Electronic address:
Photocatalytically reducing CO into high-value-added chemical materials has surfaced as a viable strategy for harnessing solar energy and mitigating the greenhouse effect. But the inadequate separation of the photogenerated electron-hole pair remains a major obstacle to CO photoreduction. Constructing heterostructure photocatalysts with efficient interface charge transfer is a promising approach to solving the above problems.
View Article and Find Full Text PDFNanomicro Lett
December 2024
Department of Chemistry and Laboratory of Advanced Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, State Key Laboratory of Molecular Engineering of Polymers, Collaborative Innovation Center of Chemistry for Energy Materials (2011-iChEM), College of Chemistry and Materials, Fudan University, Shanghai, People's Republic of China.
Chloroform and other volatile organic pollutants have garnered widespread attention from the public and researchers, because of their potential harm to the respiratory system, nervous system, skin, and eyes. However, research on chloroform vapor sensing is still in its early stages, primarily due to the lack of specific recognition motif. Here we report a mesoporous photonic crystal sensor incorporating carbon dots-based nanoreceptor (HMSS@CDs-PCs) for enhanced chloroform sensing.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602, Japan.
PtGd alloy nanoparticles supported in hollow mesoporous carbon spheres (HMCS; ) were successfully prepared by the thermal reduction of organometallic Pt and Gd complexes without oxygen atoms supported in the pores of HMCS. The structures of PtGd alloy nanoparticles were fully characterized by TEM, HAADF-STEM-EDS, XRD, XAFS, and XPS, suggesting the formation of uniform PtGd alloy nanoparticles with an average particle size of 5.9 nm.
View Article and Find Full Text PDFNanoscale
December 2024
Key Laboratory of Advanced Energy Storage and Conversion of Wenzhou, Key Laboratory of Carbon Materials of Zhejiang Province, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, P. R. China.
Lead oxides (PbO, 1 ≤ ≤ 2) are promising high-capacity and low-cost anodes for lithium ion batteries (LIBs). However, the huge lithiation-induced volume expansion of conventional large-sized PbO particles leads to severe electrode pulverization with poor cycling stability. Herein, a rare mixed-valence PbO with a unique hierarchical architecture of nanoparticle-assembled interconnected hollow spheres (denoted PbO NAHSs) is crafted by introducing polyvinylpyrrolidone (PVP) into the solution of generating β-PbO microspheres (MSs), which is exploited for the first time as a potential advanced anode material for LIBs.
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